5 minute read
SKA-Low construction highlights
from Contact 14
BY ANT SCHINCKEL, SKA-LOW SITE CONSTRUCTION DIRECTOR
From groundworks and preparation for the first antenna installations, to establishing a paramedic service for on-site staff, it’s all go at the SKA-Low site.
First infrastructure works begin
September saw the first SKA-Low telescope-related infrastructure take place at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory. This included the first earthworks for the antenna arrays that comprise AA0.5 – the first six stations of the telescope, on the southern spiral arm.
The first clearing works were performed by Wajarri Holdings, a Wajarri-owned and operated business subcontracted by Ventia, which marked the occasion with a celebratory on-site event supported by the SKAO. Guests included representatives from the SKAO, Ventia, CSIRO, Wajarri Holdings, Wajarri Yamaji Aboriginal Corporation (WYAC), Wajarri Enterprises Limited, Aurecon and on-site subcontractors.
Four Wajarri companies have now been subcontracted for on-site infrastructure work for the project. More than 30 Wajarri people have been employed on the project on site, including infrastructure and civil works, camp village and transport, with additional Wajarri people employed through WYAC and CSIRO as heritage monitors.
A 103-bed temporary “fly camp” was also opened, providing accommodation for staff, contractors and visitors while construction of the permanent 200-bed construction camp progresses.
There has been a lot of progress on site since the celebration. Significant clearing, trenching and backfilling work has been done at the AA0.5 telescope stations, and power and fibre optic cables have begun to be laid. The pouring of the foundations for the remote processing facilities for AA0.5 has commenced. The on-site connections to existing fibre optic cables that link to supercomputers located more than 600 km away at the Pawsey Supercomputing Research Centre in Perth will be installed in the coming months. As of early November, around 80% of the core area has been cleared in preparation for infrastructure works.
AAVS3 commissioning underway
The team completed installation of Aperture Array Verification System 3 (AAVS3), the final SKA-Low technology demonstrator on site. AAVS3 is the first instrument owned, operated and maintained by SKAO staff in Australia. Representing a single complete SKA-Low station, AAVS3 is being used to trial an alternative layout, with a goal of confirming the layout with the least possible electrical interference between antennas. It is also an opportunity to test the building processes of the first SKA-Low stations, as well as the first building blocks for the verification of the telescope. With power and fibre cables connected, testing and commissioning has been taking place in collaboration with partners at Curtin University.
The SKAO team in Australia recently captured the “first light” from AAVS3, meaning the first image of the sky taken by a telescope after construction. The scientists produced the first “fringes” which measure the interference patterns produced by pairs of antennas, effectively confirming that the telescope is working correctly. The fringes were then processed after calibration to generate an image of the full sky above the station, showing the radio trace of our galaxy, as well as the Sun and the Centaurus A galaxy.
Site safety
With staff and contractor safety the highest priority during construction and beyond, the SKAO has awarded a contract to St John Ambulance WA to provide paramedic support on the SKA-Low site. A paramedic will be based on site to provide medical assessment, treatment and clinical care during the day, as well as be on-call for after-hours support.
Care for the environment
As construction progresses, the SKAO’s ecological and environmental commitments are paramount, and are already being put into action. The region which is becoming home to SKA-Low is also home to a vulnerable species of lizard: the western spiny-tailed skink. To ensure construction operations don’t impact this native creature, the first western spiny-tailed skink survey programme took place in September, with SKA-Low staff accompanying a fauna specialist as they searched for evidence of the lizards’ presence. No evidence was found, and the first clearing permit was issued for clearing work associated with AA0.5. That is not the end of the checks though, and a small number of SKA-Low staff in Australia have since been approved as fauna specialists to lead future surveys.
BEYOND THE SITE
The roll out of SKA-Low telescope SMART boxes, which will provide electrical power to the antennas and collect signals received from the sky to go off-site for processing, has begun in Australia. Perth-based company AVI is contracted to build up to 12,000 of the boxes for the entire fit-out of SKA-Low. Teams from the International Centre for Radio Astronomy Research’s Curtin University node designed and built the first set of 24 SMART boxes, which were 10 years in the making.
Work is underway to manufacture a reverberation chamber for SKA-Low activities in Australia, which will be used to undertake the emissions compliance testing of SKA-Low telescope systems and associated hardware The €1m contract will be fulfilled by Spanish company EMITE OTA test systems, together with Australian partner company Maser.
